Manufacture of solidified alcohols



Oct. 18, 1955 J. E. SCHULTZE MANUFACTURE OF SOLIDIFIED ALCOHOLS Filed Sept. 8, 1951 W 4 M I INVEN TOR. (706/) E Scfiu/fze ATTORN Ys MANUFACTURE or SOLIDlFIED ALcoHoLs John E. Schultze, Baltimore, Md., assignor to National Distillers Products Corporation, New York, N. Y., a corporation of Virginia Application September 8, 1951, Serial No. 245,735

3 Claims. (Cl. 447) This invention relates to solidified alcohols such as conventionally used as fuels and more particularly to improvements in the process of solidifying the liquid mixtures involved. The invention also provides a solidi fied alcohol fuel of more nearly homogeneous composition than heretofore available.

In the manufacture of solid fuels of predominantly alcoholic composition it is customary to prepare a solution of nitrocellulose in a solvent which consists essentially of ethyl alcohol, methyl alcohol or a mixture of the two alcohols. Other solvents may be present in smaller proportions for the purpose of facilitating solution of the nitrocellulose in the alcoholic solvent. Such minor additions may consist of acetone, methyl ethyl ketone, ethyl acetate or other suitable solvents or solvent aids.

The solutions of nitrocellulose are solidified or gelatinized by the addition thereto of a miscible non-solvent for the nitrocellulose, usually water. For this operation, the alcoholic solution is ordinarily placed in cans, jars or other suitable containers and the non-solvent, e. g., water, is injected into the solution asla plurality of fine streams by means of a spray head placed directly above the open top of the container.

The filling of the containers andthe subsequent addition of water is generally carried out by means of automatic machinery whereby the empty containers, supported on a moving belt or other conveyor, proceed in a circular path beneath nozzles moving in the same curved path and situated above the containers and through which measured amounts of the nitrocellulose solution are automatically introduced into the containers. The latter are then transferred by the conveyor to positions beneath spray heads through which the proper amount of water, or other non-solvent of the nitrocellulose, is automatically introduced into the nitrocellulose solution. For this purpose a plurality of spray heads are caused to revolve in a circular path and the containers are moved in a similar path directly beneath the respective spray heads.

The type and amount ofnitrocellulose and the composition of the alcoholic solvent, particularly the alcoholic concentration of the latter, are so chosen that the solution is nearly saturated with respect to nitrocellulose. The addition of a non-solvent, such as Water, thus upsets the solvent-solute equilibrium and the nitrocellulose is thrown out of solution in such manner as to form a gel or solidified mass.

The portions of the solution which are adjacent to the entering streams of the non-solvent are quickly solidified. As the non-solvent difiuses through the separated gel, further quantities of the alcoholic solution become solidified.

There has been experienced in the past considerable difiiculty in obtaining a uniform gel structure throughout the container, with consequent formation of soft spots oreven pockets of liquid solution which do not solidify, probably due to their not having been reached nited States Patent by the water. Since the volume of Water which is added is considerably less than the volume of solution to be gelled, it is desirable that one obtain uniform distribution of the water throughout the entire volume of nitrocellulose solution. However, ordinary expedients, such as stirring, are not applicable.

The problem of uniform distribution of water in the solution is made more difficult by the fact that the diameter of the effective area of the spray head, that is the diameter of the area which is perforated for the passage of water, must be substantially smaller than the opening of the containers in order to allow for inaccurate centering of the spray heads above the openings.

Trouble is also frequently encountered in commercial operation due to the fact that some of the spray head openings become plugged or partially plugged with the result that one or more streams are temporarily interrupted or the direction of the water stream becomes diverted from its normal direction.

Particular trouble is encountered when using shallow containers since. under these conditions the entering streams of water form in the nitrocellulose solution a series of more or less vertical narrow solidified strings or tubes having water on the inside and liquid nitrocellulose solution on the outside thereof. While these more or less cylindrical structures are not at first firm and unyielding, they do tend to stay in an upright position and in the case of shallow containers often cause a rough and uneven surface of the final gel structure since in part they extend somewhat above the surface level of the other solidified material.

These diificulties have contributed to a lack of uniformity and less attractive appearance of the product and a resultant syneresis or bleeding of the liquid from the gel, all of which have detracted from the appearance of the resultant product. The lack of uniformity further tends to interfere with the steady even burning of the solidified fuel.

It is an object of my present invention to produce solidified alcohol of improved appearance and of more uniform gel structure throughout the container. A further object is to produce a solidified alcohol which burns more steadily and exhibits less syneresis. A still further object is to increase the solidifying rate of the solution. By'rny present invention these objects and other advantages, as appear from the following description, are attained.

I have discovered that the aforementioned difficulties may be greatly diminished and usually completely eliminated by the simple step of rotating the container about its vertical axis while introducing the water. The motion may be circulatory or eccentric with respect to the spray head. Both are effective with the maximum benefit generally being obtained by an eccentric motion.

The rotation of the can results in a more even distribution of the introduced water and tends to prevent the formation of the previously mentioned tubules, the water being injected so as to form a series of concentric bands of the precipitant.

In practice it has been found that the rotation of the solution or the container may be satisfactorily accomplished in a variety of ways. The cans may be turned as they come under the spray head by causing a rubber-coated arm, curved in an are similar to that of the circular path of the cans passing under the'spray heads, to contact the sides of the containers with sufficient pressure to push them up against the restraining wall of the moving conveyer and, by virtue of the friction between the rubber surface and the container, cause the latter to rotate while the water is being introduced. In filling large. containers of one gallon capacity or Patented Oct. 18, 1955 thereabouts, they may be, with advantage, placed upon a rotating base while the water is introduced.

The number of streams of water introduced depends upon the size of the container and the amount of water to be introduced and will vary from six to two hundred or more. The size of streams may also be varied to suit the particular conditions involved. All this is apart of the known art and forms no part of this invention.

While the gelatinizing or solidifying agent has been spoken of as water, it will be understood that it may also be a mixture of the alcoholic solvent and water if desired. The only requirement in this respect is that it be a non-solvent for the nitrocellulose and so capable of precipitating the latter from solution in the form of a gel and that it does not interfere with subsequent use of the product as a fuel.

The invention will be further described and illustrated with reference to the accompanying drawings which represent conventionally and somewhat diagrammatically one form of apparatus by which the process of the invention may, with advantage, be" carried out. It will be understood, however that the invention is of general utility and is not restricted to the particular embodiment thereof illustrated.

In the drawings, Figure 1 represents a horizontal planned view of one end of a conveyor and spray head assembly.

Figure 2 represents an end view of the assembly of Figure 1 and Figure 3' represents a modified arrangement adapted to the filling of larger containers.

In the drawing, the element 1 is a horizontally positioned conveyor for the containers 2'. The conveyor is provided with a plurality of cup-shaped receptacles 3 spaced along its upper surface and adapted to promote the centering of the containers beneath the respective spray heads 4.

These spray heads are perforated at their lower sides and are supported by pipes- 5 to which water or other suitable non-solvent for the nitrocellulose is supplied to the spray heads. These pipes 5' are, in turn, connected to a headerv 6 to which water is supplied through a suitable. conduit 7.

This spray assembly, consisting primarily of the header 6, the radially extending pipes 5 and' spray heads- 4', is suspended by suitable means as by conduit 7 and is adapted to be rotated about its vertical axis, its rotation being. so coordinated. with the movement of conveyor 1 that the spray heads are positioned just above the containers while rotating. through 180 of the arc. During this period, or a. portion thereof, water is supplied to the spray heads in position above the containers.- The amount. of water injected and the start and interruption of the injection may be controlled by an automatic valve arrangement, not shown in the drawings. Such; valve arrangement is well known tothe art and need not here be described in detail.

Asshownv in the drawings, the conveyor is supported and driven by a circular table 8 which, inturn, is r0- tatably supported by the column 9 and adapted to be rotated as by means of the gear arrangement shown at 10.

The rotation of the containers during the injection of the water is, with advantage, effected by means of a stationary member 11 positioned at the end of the conveyor and supported in any convenient means, for instance, supports 12' and 13 which are, in turn, supported by the wall 14. This member 11 is curved to coincide with the curvature of the conveyor. The stationary member, or at least the inner surface thereof, is, with advantage, covered with rubber.

In operation the containers charged with the appro priate amount of the alcohol -nitrocellulose' solution are advanced by the conveyor toward the spray assembly and as they advance, one of the spray heads comes into position directly above the open container and remains in that position with respect to the container throughout an arc of 180. In passing through this arc, or a major portion thereof, the side of the container is brought to bear upon the inner surface of the stationary member 11 and because of the friction between the rubber surface of the member 11 and the side of the container, the latter is caused to rotate. Where the containers do not fit snugly into the receptacles 3, the rotation of the container, is somewhat excentric, and while not essential, that type of rotation is especially advantageous.

As shown, more particularly, in Figure 3, the rotation of the container may be otherwise effected. In that figure, the container is represented at 15 and rests upon a turntable 16, rotatably supported by a shaft 17, the container being positioned just beneath the spray head 18 which is supported and to which water is supplied by pipe 19. In this type of operation, the container is, with: advantage, placed on the turntable so that the vertical axis; of the container does not quite coincide with the vertical: axis of the turntable. By this means, the rotation of the container is somewhat eccentric and thereby even more uniform distribution of the water in the alcohol-cellulose nitrate solution is effected.

The invention will be further illustrated by the following specific examples of advantageous applications thereof.

Using a conveyor and spray head assembly, substantially asshown in Figures f and 2 of the drawings, and cylindrical containers approximately 2 /2 inches in diameter and 1% inches deep, about 60 grams of a denatured alcohol solution of nitrocellulose, the latter containing about 12% of combined nitrogen, was placed in each of the containers as they advanced toward the spray heads, the spray heads laying. on a periphery of a circle approximately 16' inches in. diameter. The containers uniformly spaced along the conveyor were carried to and along the circular portionof the conveyor path directly beneath the respective spray heads through. an are of about 180 and, from thence, were carried on by the conveyor to be capped. Upon coming into the circular path, each contain'er was rotated about its base by means of frictional pressure applied thereto by a curved rubber capped stationary' element, substantially as shown. The respective spray heads contained a plurality of small openings positioned directly above the open containers for the injection of water intothe solution within the container and approximately 1 5 cc. of water was, in this way, injected into each of the containers during their travel through about of the curved path, the containers being rotated, as described during the entire period of water injection.

By' this procedure, there was obtained a product of improved appearanceand of more uniform gel structure than heretofore obtainable by conventional gelling methods. The product was free from pockets of ungelled liquid solution and from objectionable tubular structures projecting abovethe' surface of the gel within the cont ainer. The gelling time was also substantially reduced.

Itwill be appreciated that the method just described for rotating the containers is especially applicable to containers of substantially cylindrical transverse section, and of relatively smallsize. It will be understood, however, that the invention in its broader aspect is not so restricted. Where the container does not have a substantially cylindrical transverse section, but is somewhat square, for instance, or where the container is of a large size, holding about a gallonor more, it may be rotated during the injection of the water by other means, for instance, asshown in Figure 3 of the drawing. In this application of the" invention, the container may be partially filled with the alcoholic solution of nitrocellulose and placed on a rotatable platform positioned directly below a spray head, the platform and container being rotated by hand, or otherwise, during the water injection. Thereafter, the rotation is stopped and the container removed and capped. By this procedure substantially uniform gels may be obtained in relatively large, or squareshaped containers. Usually where this procedure is employed, I find it advantageous to so position the container on the rotatable platform as to obtain an eccentric rotation.

The contents of such large size containers are generally removed in small portions for use as fuel in chafing dishes, or the like, and it is, therefore, particularly important that the solution be uniformly gelled and that there be a minimum of free liquid present due to incomplete gelling or syneresis. By the procedure just described, such objectionable characteristics of the congealed fuel are substantially completely avoided.

It will, of course, be understood that, instead of rotating the container, the spray head may be rotated, or both spray head and container may be rotated, in opposite directions. This relative rotation, as previously noted, tends to cause the water to enter the solution so as to form initially a series of concentric bands of gelled structure, instead of the strings or tubes previously encountered.

I claim:

1. In the process of producing solidified alcohols where in an alcohol solution of nitrocellulose is solidified by injecting into the solution from above the upper surface thereof a miscible non-solvent for the nitrocellulose as a plurality of fine streams, the step of producing relative rotation between the solution and said streams about a vertical axis during said injection.

2. In the process of producing solidified alcohols wherein an alcoholic solution of nitrocellulose is placed in an open container and solidified therein by injecting into the solution by means of a spray head positioned above the container a miscible non-solvent for the nitrocellulose as a plurality of fine streams, the step of producing relative rotation between the container and the spray head about its vertical axis during the injecting of the said nonsolvent into the solution.

3. The step of claim 2 in which the rotation of the container is eccentric with respect to the spray head.

References Cited in the file of this patent UNITED STATES PATENTS Wyler Apr. 1, 1930 Jones et a1. Dec. 14, 1937 OTHER REFERENCES 

1. IN THE PROCESS OF PRODUCING SOLIDIFIED ALCOHOLS WHEREIN AN ALCOHOL SOLUTION OF NITROCELLULOSE IS SOLIDIFIED BY INJECTING INTO THE SOLUTION FROM ABOVE THE UPPER SURFACE THEREOF A MISCIBLE NON-SOLVENT FOR THE NITROCELLULOSE AS A PLURALITY OF FINE STREAMS, THE STEP OF PRODUCING RELATIVE ROTATION BETWEEN THE SOLUTION AND SAID STREAMS ABOUT A VERTICAL AXIS DURING SAID INJECTION. 